NullPointerException when running Concrete Simulator

[mikaelbdj]

Describe the bug
In one case, after generating a strategy for a Timed Game, when I run the Concrete Simulator with the generated strategy I get a NullPointerException. In this particular case it happens in a deadlocked state, but I am not sure if it is pertinent to the bug.

To Reproduce
Steps to reproduce the behavior:

1. Open the model: strategy_example.zip
2. Execute the first query to generate a strategy
3. Open Concrete Simulator
4. Choose Goal as the strategy and click "Stochastic"
5. If the Simulator moves directly to 'Win' (20% chance), redo steps 2-4 after reloading.
6. The simulator will move to L1 and freeze for a few seconds and the error occurs.

Expected behavior
I don't get a NullPointerException and the simulator simply stops if there is a deadlock.

Version(s) of UPPAAL tested
5.0.0

Screenshots

Desktop:

• Version 5.0.0
• OS, Java version: Ubuntu 22.04.4 LTS, openjdk 17.0.12 2024-07-16